The proposed study investigates radiation-mortality associations in a cohort of workers employed at the US Department of Energy's Y-12 uranium processing facility. The Y-12 cohort was recently expanded, and vital status information was updated through 1990. Radiation lung dose estimates for Workers at Y-12, based on bioassay and in vivo monitoring records, are available in computerized brim. However, no analyses of dose-response associations have been conducted using this updated information. The proposed research will take advantage of this previously collected data in order to conduct investigations of occupational exposure-disease associations. Detailed analyses will be conducted of variation in radiation-mortality associations with latency, time-since-exposure, and age-at-exposure. The results of this study will help to address analytical questions about radiation-lung cancer associations in this cohort, while reducing exposure misclassification by better identifying the etiologically-relevant time period of exposure.